Fix broken links to mdo papers
Fix broken links to mdo papers

There's no guarantee that the links will work in the future.
Is there a more future-proof solution to this?

Test Plan: none

Reviewers: bgamari, austin, simonmar

Reviewed By: simonmar

Subscribers: thomie, simonmar

Differential Revision: https://phabricator.haskell.org/D2266

snoyberg/ghc,snoyberg/ghc,sdiehl/ghc,snoyberg/ghc,ezyang/ghc,snoyberg/ghc,vTurbine/ghc,olsner/ghc,snoyberg/ghc,olsner/ghc,sdiehl/ghc,snoyberg/ghc,olsner/ghc,sgillespie/ghc,sdiehl/ghc,shlevy/ghc,ezyang/ghc,olsner/ghc,vikraman/ghc,vikraman/ghc,vTurbine/ghc,shlevy/ghc,ezyang/ghc,sgillespie/ghc,vTurbine/ghc,sdiehl/ghc,vikraman/ghc,mettekou/ghc,vTurbine/ghc,sgillespie/ghc,sdiehl/ghc,shlevy/ghc,shlevy/ghc,mettekou/ghc,mettekou/ghc,ezyang/ghc,olsner/ghc,vTurbine/ghc,sgillespie/ghc,mettekou/ghc,mettekou/ghc,vikraman/ghc,sdiehl/ghc,ezyang/ghc,mettekou/ghc,mettekou/ghc,sgillespie/ghc,olsner/ghc,ezyang/ghc,vTurbine/ghc,vikraman/ghc,sgillespie/ghc,sgillespie/ghc,sdiehl/ghc,shlevy/ghc,shlevy/ghc,vikraman/ghc,vikraman/ghc,snoyberg/ghc,ezyang/ghc,shlevy/ghc,vTurbine/ghc,olsner/ghc